First mass-produced target drone

The OQ-2 by USA-based "Radioplane" became the first mass-produced drone in aviation history. Based on the RP-1 prototype model demonstrated to the US Army in 1935, this little radio-controlled drone went through a number of prototype evolutions until, in 1939, the RP-4 was bought by the US Army Air Corps for target-practice purposes. The drone was powered by a two-cylinder piston engine providing 6 horsepower (4.5 kW) and driving two contra-rotating propellers. The control system was built by Bendix (USA). Launching was by means of a catapult and the drone was recovered by parachute if it survived the target practice. Radioplane went on to make around 15,000 of the drones.